1. Field of the Invention
The present invention relates to chemically reactive fragmentation warheads. More particularly, the fragmentation warheads of the present invention contain an energetic material of organic nitrate esters imbedded into a polar imbiber agent. Most particularly, the organic nitrate esters of the present invention are complexed with a nitrate ester plasticizer, bismuth subsalicylate and stabilizer to form highly energetic compositions with a stability and sensitivity suitable for use within a fragmentation warhead.
2. Brief Description of the Related Art
Several types of warheads are known. Previously known warheads include reactive metals housed within the casing of the warhead that react rapidly with the medium in which the explosion takes place, e.g., air, or with a material component of the target. U.S. Pat. No. 5,852,256 to Hornig discloses a non-focused blast explosive having a high explosive surrounded by an active metal that is capable of chemically interacting with the environment that is dispersed in fine particles when detonation occurs.
Other types of known warheads include chemically burning devices incorporated into void areas of a carrier, such as a polymer matrix. U.S. Pat. No. 3,951,066 to Schroeder discloses an incendiary fragmentation device with frangible but not detonatable incendiary material imbedded in a high explosive charge. U.S. Pat. No. 4,547,234 Takeuchi et al. discloses an explosive composition containing micro-voids.
Another type of warhead, known as fuel-air explosives, has an air combustible hydrocarbon, such as gasoline, disposed in a suitable tank surrounding a central charge of high explosive. Detonation of the high explosive disperses the hydrocarbon into a vapor cloud that is ignited by a secondary delayed charge. These warheads have significant handling and storage limitations, particularly with regard to leakage.
Fragmentation and scattering types of warheads use a high explosive center charge that fragments a surrounding material, such as a heavy steel outer casing. U.S. Pat. No. 1,015,215 to Sokolowski discloses a uniform projectile for guns in which scattering charges are embedded in plastic trinitrotoluol. U.S. Pat. No. 3,728,174 to Reinhart discloses hollow-resinous plastic spheres in a dynamite to provide resistance to collapse at high pressure. U.S. Pat. No. 4,706,568 to Lundwall et al. discloses a chemiluminescent lighting structure containing a plurality of smaller chemiluminiscent light sources.
Explosive compositions and propellants also are known. U.S. Pat. No. 5,114,506 to Consaga et al. discloses an energetic gun propellant or explosive composite having a solid nitrate ester of cyclodextrin and nitroglycerin. U.S. Pat. No. 5,454,891 to Preston discloses nitrated esters useful in explosives and gun propellants. U.S. Pat. No. 5,472,529 to Arita et al. discloses an explosive composition having an oxidizer, water and organic hollow microspheres, and a sensitizer composed of an organic or inorganic nitrates. U.S. Pat. No. 5,639,987 to Berteleau et al. discloses a solid propellant containing cellulose nitrate and nitroglycerin, with the use of bismuth salicylate. U.S. Pat. No. 5,652,409 to Thompson et al. discloses an uncomplexed double-base propellant having cyclodextrin nitrate, nitroglycerin, and bismuth salicylate in a double base propellant.
None of these patents discloses a reactive fragmentation warhead having a highly stable, safe handling composition that is detonated on impact. In view of the foregoing, there is a need for a warhead having a highly stable explosive energetic material that may be formed into a cloud and contact detonated. The present invention addresses this and other needs.